Mac laptop backup in the Nevis particle-physics network

Would you like a spare backup in case you lose both your laptop and backup drive?

Then this page is for you!

Quick warnings

This should not be your only laptop backup.

This only works when your Mac laptop is at Nevis, connected either via the particle-physics wireless or wired network.

This is only for Time Machine backups. If you just want to off-load your files somewhere, you'll need a different solution.

If you're using more than 200GB of your laptop's hard drive, we may run out of space quickly (see below).

How-to

You can bring your laptop to WilliamSeligman's office and he'll set it up for you. If you want to do it yourself, the following steps only have to be carried out once.

From the Finder, select the menu Go -> Connect to Server... (or just type Command-K).

For "Server Address", enter afp://tanya.nevis.columbia.edu and click the "Connect" button.

You'll be prompted for an account name and password. Enter your Linux cluster account information, not your laptop account name or password. Hit the "Enter" key when you're done.

In the list you'll see, select "Macintosh Time Machine" and click the "OK" button. (Don't bother with any other options; they won't do what you think they'll do.)

From the Apple menu, select System Preferences, then Time Machine.

Click the "Select Disk" button. After a couple of seconds, you should see "Macintosh Time Machine" in the list. Click on it, then click the "Use Disk" button.

On the next panel, select "Use Both". (This will happen if you've already set up a Time Machine backup on some other disk.)

Click on the "Options" button:

Turn off the "Notify after old backups are deleted" option.

In the "Exclude these items from backups" panel, please pleaseplease add any folders whose contents you could re-download or re-sync if necessary. Examples:

iTunes items (~/Music/iTunes/iTunes Music).

Cloud services (e.g., ~/Dropbox, ~/Google Drive).

Mail folders if you've set your mail reader to download mail for offline reading (e.g., ~/Library/Mail, ~/Library/Thunderbird). Note that this mean your other mail settings (e.g., address book, custom spam filters) won't be backed up either unless you tweak the folder exclusion to go down to the profile level.

However, these exclusions will apply to your other Time Machine backup(s) as well. If these exclusions are not acceptable for your other backup, then don't exclude them here.

Click the "Save" button.

You're done! Your Mac laptop will start syncing automatically, and will re-sync automatically whenever you work at Nevis. You can restore files from the backup using the Time Machine program in your Applications folder.

Limitations

This is a more ad-hoc setup than the main backups we do on for the Linux cluster and the electronics-design computers. The Time Machine backup is located on a 6TB RAID disk enclosure connected to WilliamSeligman's desktop machine in room 116. If something goes wrong with that desktop or that RAID array, the Time Machine service goes down as well.

6TB sounds like a lot, but it's not. Recall how Time Machine works: it keeps copying new versions of files from your laptop to the backup and keeps all the old versions. Only when the backup fills up does it start deleting file versions, the oldest first. Now consider that everyone else's Mac laptop is doing the same thing. At some point the backup sets are going to "bump into each other."

That's why I emphasize not backing up files that are frequently updated but easy to recreate (mail) or files backed up elsewhere (cloud services).

This service is only available to laptops running Mac OS X. There is no common equivalent to Time Machine on Windows or Linux systems (e.g., automatic backup on network connection, maintaining file versions, ease of restoration, auto-deletion of old versions when disk space runs out).